JPS6120855A - Display system of pattern by isotope existence ratio - Google Patents

Abstract

PURPOSE:To permit the easy contrast of measuring data and theoretical value and the easy identification of the difference therebetween by displaying superposedly the pattern of the calculated theoretical value and the pattern of the measuring data by different display modes. CONSTITUTION:A measuring data standardizing part 3 standardizes the entire part of the measuring data with the intensity of the molecular peak or fragment peak selected by the operator as 100% out of the measuring data obtd. by a mass spectrometer 1. An isotope peak calculating part 4 calculates the number of the isotope peak systems by using the compsn. formula for the molecular peak or fragment peak given in accordance with the isotope existence ratio registered in a table 5. A video control part 6 delivers the pattern for the result of the processing in the part 3 after converting the same into, for example, a blue video signal and a video control part 7 delivers the pattern calculated in the part 3 after converting the same to, for example, a red video signal. These video signals are added 8 and are drawn on the same CRT of a display part 9. The superposed part is therefore made into the combined color of the red and blue and the non-superposed part is made into the red or blue color. The contrast is thus made easy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mass spectrometry data analysis system, and relates to a display of a pattern based on isotope abundance ratio in which a pattern based on isotope abundance ratio is displayed superimposed on a pattern of measurement data. It is related to the method.

[Conventional technology]

In mass spectrometry data, no difference in isotopic patterns appears when the molecular weight is small, but as the molecular weight increases, its influence becomes apparent. Based on this tendency, it is possible to identify the compositional formula of the spectrum by referring to the isotope pattern.

Figure 1 shows methyl stearate t・(C+ q H380z
) shows an example of a mass spectrum.

In the example of the mass spectrum shown in Figure 1, the mass number M/Z
There is a peak at =298. However, strictly speaking, this peak has a mass number M/Z = 298.1157 and a peak value of 33.
．． For 10 peaks, the following 5 groups are possible according to the calculation.

C22Hsa (150,3mmu)Cz+ H3
00(113,9mmu)CzoH4z○ (-207
,8mmu)Czo H2602(77,6mmu)C
I9H3802 (171.4 mmu) The value in parentheses above indicates the mass number error (mmu; millimeter unit).

FIG. 2 shows an example of calculating a theoretical pattern from the abundance ratio of isotopic values for each of these. Of the figures (a) to e) shown in Figure 2, the data in (e) is a logical calculation for the correct answer, so the mass spectrum shown in Figure 1
In the data, mass number M/Z = 298.299.3
It is sufficient that the three peaks of 00 match the data shown in FIG. 2(e). However, in normal cases, there is also measurement error, and complete agreement does not occur.

When identifying the composition formula using the isotope pattern as a reference for the peak of the mass spectrum data as described above,
Conventionally, for measurement data, the entire pattern was
Normalized to base peak etc. as spectrum and transmitted to CRT
Shown above.

On the other hand, the isotope abundance ratio is calculated theoretically based on the elements and their numbers included in the composition formula, and the calculated numerical information is kept as a document, and the document can be referred to or the contents of this document can be translated into a computer. The compositional formula was identified by using off-line information that was calculated and output as a pattern on a CRT.

[Problem that the invention seeks to solve]

However, as mentioned above, even if we refer to the conventional ridge literature or use offline information outputted as a pattern on a CRT, it is difficult to decipher the difference between the measured data and the theoretical value. In view of this, the present invention aims to provide a method for displaying patterns based on isotope abundance ratios, which allows easy comparison of measured data and theoretical values, and allows easy reading of differences between them. This is the purpose.

[Means for solving problems]

For this reason, the method of displaying patterns based on isotope abundance ratios of the present invention is to display patterns based on isotope abundance ratios superimposed on measurement data patterns using the mass number and the intensity corresponding to the mass numbers as coordinate axes. A pattern display method according to the present invention, comprising a calculation means for calculating a coefficient of an isotope peak using a composition formula of a molecular peak given based on an isotope abundance ratio, and a display control means, the display control means comprising: The present invention is characterized in that the pattern calculated by the calculation means and the pattern of the measurement data are displayed in different display modes in an overlapping manner.

[Effect]

In the method of displaying patterns based on isotope abundance ratios of the present invention,
When the composition formula of the molecular peak constituting the measurement data is given, the calculation means calculates the coefficients of the k isotope peaks based on the isotope abundance ratio, and sends the pattern to the display control means. On the other hand, the display control means displays the pattern of the measured data according to a pre-designated display mode, and also superimposes the pattern calculated by the calculation means on top of the pattern. the result,
Overlapping portions and non-overlapping portions of both patterns are displayed in different display modes on the same screen.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a diagram explaining one embodiment of the present invention, and FIG. 4 is a diagram showing an example of displaying a pattern based on isotope abundance ratio to which the present invention is applied. In Fig. 3, 1 is a mass spectrometer, 2 is an input section, 3 is a measurement data standardization section, 4 is an isotope peak calculation section, 5 is a table, 6 and 7 are video control sections, 8 is an addition gate, 9 indicate the respective display parts. The measurement data standardization unit 3 standardizes the entire measurement data by setting the intensity of the molecular peak or fragment peak selected by the operator (input instruction from the input unit 2) as 100% from the measurement data obtained by the mass spectrometer 1. It is the one that carries out the transformation.

Table 5 is a record of isotope abundance ratios, and the isotope peak calculation unit 4 calculates the composition formula of a given molecular peak or fragment peak based on the isotope abundance ratios registered in Table 5. This is used to calculate the isotope peak coefficient. The video control unit 6 has a mass number? The processing result pattern of the measurement data normalization unit 3 is sent out as a blue video signal, for example, with I/Z as the horizontal axis and intensity as the vertical axis, and the video control unit 7 sends the mass number M/Z as the horizontal axis and the intensity as a blue video signal. The calculation pattern of the isotope peak calculation unit 4 is converted into, for example, a red video signal and sent out with the vertical axis being . These video signals are added by an adding section 8 and sent to a display section 9. Therefore, on the display unit 9, the mass number M/Z is displayed on the horizontal axis,
A mass spectrum bar graph with intensity as the vertical axis is drawn. Therefore, the overlapping parts are displayed in a composite color of red and blue, and the non-overlapping parts are displayed in red or blue. FIG. 4 shows an example of the display. In FIG. 4, each color tone is represented by a thin line, a wide line with a white inside, and a thick line with a filled inside.

Note that, as described above, instead of using the Millimas data composition calculation results, the coefficients of the pattern based on the isotope abundance ratio may be calculated by manually inputting the composition formula, and the coefficients may be displayed superimposed on the low-resolution data pattern. Needless to say. Furthermore, it is not only possible to overlay the horizontal axes using different tones such as red and blue, but also to overlay the measured data and theoretical values with the horizontal axes shifted so that they can be distinguished by symbols. good. Such display is rather effective when, for example, a plotter or monochrome CRT is used instead of a color monitor.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, Bakun coefficients based on isotope abundance ratios are displayed superimposed on measurement data on the same screen by color-coding and shifting the horizontal axis, making it possible to identify This makes it easier to judge, making identification work more efficient and improving reliability. This is particularly effective when the mass number becomes large or for molecular peaks containing more elements. According to the present invention, for example, when the pattern ratio is significantly different, it becomes clear that there is an impurity, that is, the assumed compositional formula is incorrect.

[Brief explanation of drawings]

Figure 1 shows an example of a mass spectrum of methyl stearate, Figure 2 shows an example of calculating a theoretical pattern from the abundance ratio of isotopes, and Figure 3 explains one embodiment of the present invention. 4 are diagrams showing examples of displaying patterns based on isotope abundance ratios to which the present invention is applied. DESCRIPTION OF SYMBOLS 1... Mass spectrometer, 2... Input section, 3... Measured data normalization section, 4... Isotope peak calculation section, 5...
Tables 6 and 7... Video control section, 8... Addition section, 9... Display section.

Claims (2)

[Claims] (1) A pattern display method based on isotope abundance ratios in which a pattern based on isotope abundance ratios is displayed superimposed on measurement data using mass numbers and the intensity corresponding to the mass numbers as coordinate axes,
It is equipped with a calculation means and display control means for calculating coefficients of isotope peaks using the compositional formula of the molecular peak given based on the isotope abundance ratio, and the display control means is configured to calculate the pattern calculated by the calculation means and the display control means. A method of displaying patterns based on isotope abundance ratios, characterized in that the pattern of the measurement data is displayed in a different display manner in an overlapping manner. (2) The display control means is configured to display the pattern calculated by the calculation means and the pattern of the measurement data overlappingly in different colors. Pattern display method based on body abundance ratio.